Method for inkjet textile printing

ABSTRACT

Method for inkjet textile printing comprising a printing step for printing an aqueous pigment ink on a specifically pretreated portion of a textile fiber product by an inkjet process, 
     wherein said specific pretreatment is performed by applying at least: 
     
         
         (A) a quaternary ammonium salt type cationic surfactant represented by the formula (1) below, and 
         (B) a block isocyanate compound to the entire textile fiber product or a required portion thereof, and said aqueous pigment ink comprises at least a pigment, an aqueous liquid as a solvent or dispersion medium, and: 
         (C) a water-soluble dispersing agent having a crosslinking property, 
         (D) a self-emulsifying type urethane resin, and 
         (E) a block isocyanate compound. 
       
    
                         
[Two of R 1  to R 4 : alkyl having 8 to 18 carbon atoms; the remaining two: methyl or ethyl; X − : anion.]

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a method for inkjet textile printingwherein an aqueous pigment ink is inkjet-printed on a textile fiberproduct after pretreatment and a textile fiber product prepared usingthe method.

2. Description of the Prior Art

In recent years, inkjet textile printing with an ink containing a dye orpigment as a colorant has been developed as a method of coloring atextile fiber product with the advantage of obviation of the need forplate making.

In the case of coloring with a dye, a textile fiber product, pretreatedwith a cellulose thickener or the like in advance, is theninkjet-printed with an ink containing a dye suitable for the kind offiber as a colorant. Accordingly, inks containing reactive dyes ordirect dyes for cellulose fibers such as cotton or hemp, acid dyes foranimal fibers such as wool or silk, acid dyes or disperse dyes for nylonfibers, disperse dyes for polyester fibers, and cationic dyes foracrylic fibers, are used as colorants respectively. After inkjetprinting, steps for steaming, washing, soaping, drying and so on aretaken to yield a textile fiber product with desired pattern withoutplate making.

However, because a dye is used as a colorant, it is necessary to changethe dye (hence the ink containing the dye) according to the kind offiber, and problems arise from the complex processes following inkjetprinting, such as for steaming, washing, soaping, and drying, and atendency for increasing environmental load.

Meanwhile, in the case of coloring with an ink containing a pigment,which, unlike dyes, is a colorant that does not have substantivity forfibers, there are advantages in that unlike dyes, textile fiber productsof various fibers can be colored with a single kind of ink, and that theenvironmental load is low because of the obviation of the need forsteaming and washing steps after printing, although a binder is neededto bind the pigment to the fiber.

However, because pigments, unlike dyes, occur as insolublecolor-imparting particles, inkjet printing using a pigment ink poses theproblems of clogging in the fine nozzle of inkjet printing machine andthe possible occurrence of time-related precipitation and flocculationof the pigment in the ink. The same poses other problems, including atendency for film formation on the nozzle tip of inkjet printing machineand hence nozzle clogging caused by the binder needed to bind thepigment to the fiber, a tendency toward a hard feeling, and difficultyin obtaining sufficient fastness. Still another problem can arise when apigment ink is printed directly on fiber: the pigment ink penetrates thefiber, making it difficult to obtain high-density patterns, and thepigment ink undergoes migration, making it difficult to obtain brilliantimages.

Examples of past proposals concerning color impartment by an inkjetprocess using a pigment as a colorant include the techniques describedin the references (1) to (6) below.

(1) JP-A-2003-268271

A technique for performing inkjet textile printing with excellentperformance in printing stability, discharge stability, storagestability, and washing fastness by dispersing a pigment using an organicpolymer compound having an anionic group, previously polymerized in asolvent, thereafter distilling off the solvent, adding an acid for aciddeposition to cover the pigment surface with the organic polymercompound, and thereafter heating a fabric inkjet-printed using an inkprepared by blending a block isocyanate in a colorant solubilized by theaddition of water and a base.

(2) JP-A-2009-215506

A technique for using a ink for inkjet textile printing to print afabric comprising a pigment, a water-dispersible resin, a blockisocyanate compound as a crosslinking agent, and water, and exhibitinggood performance in color fastness to washing and rubbing.

(3) JP-A-2006-218791

A technique for using an inkjet recording material that exhibitsexcellent performance in image brilliancy, water resistance, lightresistance, and chromogenicity, comprising a polylactic acid fiber baseand an ink receiving layer formed thereon, the layer comprising anaqueous emulsion type acrylic adhesive having a glass transition pointranging from −50° C. to −10° C. and a water-soluble cationic polymer asprimary components.

(4) JP-A-2009-215686

A method for inkjet textile printing having both high color fastness torubbing and excellent chromogenicity and brilliancy, comprisingpretreating a fabric with a water dispersion of a cationic polymer,thereafter coloring the fabric by inkjet, then post-treating with adispersion of a block isocyanate in water, and heating at 120° C. to210° C.

(5) JP-T-2010-503779

A method for digital printing of a fabric, comprising

-   (a) a step for pretreating the fabric with an aqueous pretreatment    solution containing a nonionic latex polymer and a polyvalent cation    salt solution,-   (b) a step for drying the pretreated fabric, and-   (c) a step for digital printing the dry pretreated fabric with a    color inkjet ink,    wherein the nonionic latex polymer has a sufficient nonionic    component to make it stable in the presence of the polyvalent cation    salt solution.

(6) JP-A-HEI-11-315485

A technique concerning an inkjet-printed fabric having (a) an aqueousink comprising an aqueous vehicle and a colorant and (b) a fabric to beprinted with the aqueous ink, wherein the fabric has been treated with ahydrophilic composition containing at least one kind of crosslinkablethermoplastic polymer having a molecular weight of at least 6000, andselected from the group consisting of (1) a polymer having at least onecarboxylic acid group and at least one crosslinkable group and (2) apolymer selected from the group consisting of mixtures of a firstpolymer having at least one carboxylic acid group and a second polymerhaving at least one crosslinkable group.

However, the proposals described in the aforementioned references (1) to(6) are problematic in the aspects shown below.

The technique described in the reference (1) cannot be said to be anappropriate method of obtaining a colorant because it requires thecomplex steps of once finely dispersing a pigment in a solvent system,then performing acid deposition to bind an organic polymer compound tothe pigment surface, and thereafter blending a base to solubilize thepigment to obtain a colorant, its workability is low, and its process ispainstaking. In addition, the pigment dispersion prepared by dispersinga pigment using such a pigment-dispersing agent is highly viscous, andwhen the pigment is dispersed to high density, the ink viscosityincreases to the extent that the ink cannot be used for inkjet;therefore, the pigment dispersion is not considered to be suitable foran inkjet ink of high color density. In addition, when a fabric iscolored with this ink formulated with a block isocyanate and subjectedto a heat treatment, the bindability of the ink component to the fabricis weak, and it is unlikely that satisfactory fastness is obtained.

In the technique described in the reference (2), like the techniquedescribed in the reference (1), a block isocyanate compound isformulated as a crosslinking agent in a coloring ink only, and thecrosslinking of the water-dispersible resin and block isocyanatecompound in the coloring ink alone does not cause sufficient pigmentbinding to the fabric; therefore, this technique is not considered toensure adequate fastness.

In the technique described in the reference (3), a fiber base ispretreated with a composition of an aqueous emulsion type acrylicadhesive and a water-soluble cationic polymer as the primary componentsin advance to cover the entire surface of the fiber base with a resinfilm; therefore, it is thought that the feeling of the fiber basehardens, and that the breathability is adversely affected. In addition,because inkjet printing is performed on a hydrophobic film, it isthought that brilliant images are difficult to obtain due to inkrepellency.

The technique described in the reference (4) is intended to improve thefastness by pretreating a fabric with a cationic polymer to increase thecolor development density of inkjet prints, and post-treating the fabricwith a block isocyanate compound; however, pretreatment with the polymerhardens the feeling. In addition, when inkjet printing is followed by apost-treatment with a block isocyanate, crosslinking of the binder andblock isocyanate in the coloring ink occurs, improving the waterresistance of the binder; however, the binding of the fabric and thepigment and binder is insufficient; therefore, this technique is notconsidered to ensure adequate fastness for a colored fabric.

The techniques described in the references (5) and (6), like thetechnique described in the reference (4), are considered to adverselyaffect the feeling because of pretreatment of the fabric with a polymer,and to make it difficult to obtain brilliant images due to inkrepellency because of inkjet printing on a hydrophobic film.

As stated above, when using a dye as a colorant in coloring a textilefiber product by an inkjet process, clogging in the nozzle of inkjetapparatus is unlikely to occur, the ink discharge stability is good, andwith dyeing affinity for fiber, the quality properties such as feelingand fastness of the colored textile fiber product are good. In thiscase, however, it is necessary to choose a dye according to the kind offiber, and moreover, problems arise from the complex steps that cannotbe said to be efficient, the cost requirements for equipment andresource consumption, and the relatively high environmental load bywaste liquid.

Meanwhile, when using a pigment as a colorant in coloring a textilefiber product by an inkjet process, it is unnecessary to choose apigment according to the kind of fiber, and the steps are relativelysimple; however, this method poses problems concerning the long-termstorage stability of the pigment ink, possible occurrence of clogging inthe nozzle of inkjet apparatus and discharge stability reduction, anddifficulty in obtaining good quality properties such as feeling andfastness of the colored textile fiber product.

For this reason, there is a demand for the development of a method ofcoloring a textile fiber product by an inkjet process using an inkcontaining a pigment as a colorant, which method enables the obtainmentof brilliant images and a colored product with excellent color fastnessand soft feeling while preventing clogging in the fine nozzle of inkjetprinting machine.

SUMMARY OF THE INVENTION

The present invention has been developed in view of the above-describedproblems in the conventional art, and is intended to provide a methodfor inkjet textile printing that allows a textile fiber product to bebrilliantly colored using a pigment ink with good quality-relatedproperties such as feeling and color fastness, while preventing cloggingin the nozzle of inkjet printing machine, and a textile fiber productprepared using the same.

[1] The present inventors conducted extensive investigations to solvethe above-described problems, and have succeeded in developing a methodfor inkjet textile printing that allows a textile fiber product to bepigment-colored with soft feeling and excellent fastness by pretreatinga subject textile fiber product with a particular cationic surfactantand block isocyanate compound, and thereafter inkjet-printing thesubject textile fiber product with an aqueous pigment ink containing atleast a water-soluble dispersing agent having a crosslinking property, aself-emulsifying type urethane resin, and a block isocyanate compound.

According to this method for inkjet textile printing, by pretreating atextile fiber product with a particular cationic surfactant and blockisocyanate compound, inkjet textile printing of the textile fiberproduct with an aqueous pigment ink can be performed brilliantly andwith high density while preventing bleeding and penetration to themaximum possible extent, and the block isocyanate compound used in thepretreatment and/or a block isocyanate compound in the aqueous pigmentink crosslink with the water-soluble dispersing agent having acrosslinking property and/or the crosslinking functional group in theself-emulsifying type urethane resin in the aqueous pigment ink, so thatthe water-soluble dispersing agent, the self-emulsifying type urethaneresin, and the block isocyanate compound become a water-insolubleintegral entity, and, while in a state containing the pigment, bindfirmly to the fiber in the textile fiber product, whereby apigment-colored textile fiber product with soft feeling and excellentfastness is obtained.

[2] The method for inkjet textile printing and textile fiber product ofthe present invention can be described as follows:

1. A method for inkjet textile printing comprising a printing step forprinting an aqueous pigment ink on a specifically pretreated portion ofa textile fiber product by an inkjet process,

wherein said specific pretreatment is performed by applying at least:

-   (A) a quaternary ammonium salt type cationic surfactant represented    by the formula (1) below, and-   (B) a block isocyanate compound to the entire textile fiber product    or a required portion thereof, and said aqueous pigment ink    comprises at least a pigment, an aqueous liquid as a solvent or    dispersion medium, and:-   (C) a water-soluble dispersing agent having a crosslinking property,-   (D) a self-emulsifying type urethane resin, and-   (E) a block isocyanate compound.

[In the formula (1), two of R¹ to R⁴ mutually independently represent analkyl group having 8 to 18 carbon atoms, the remaining two mutuallyindependently represent a methyl group or an ethyl group, and X⁻represents an anion.]

2. The method for inkjet textile printing in 1 above, having apretreatment step for performing the specific pretreatment on the entiretextile fiber product or a required portion thereof prior to saidprinting step.

3. The method for inkjet textile printing in 1 or 2 above wherein thepretreatment is performed by applying a pretreatment agent containing atleast:

-   (A) a cationic surfactant represented by the formula (1) and-   (B) a block isocyanate compound to the entire textile fiber product    or a required portion thereof.

4. The method for inkjet textile printing in 1, 2 or 3 above wherein (B)the block isocyanate compound is a compound resulting from blocking ofthe isocyanate group in

-   trimethylolpropane adduct form or isocyanurate form of:-   hexamethylene diisocyanate,-   hydrogenated xylylene diisocyanate,-   isophorone diisocyanate, or-   dicyclohexylmethane diisocyanate.

5. The method for inkjet textile printing in 4 above wherein (B) theblock isocyanate compound has been obtained using diethyl malonate,diisopropylamine, 1,2,4-triazole, 3,5-dimethylpyrazole, or2-butanonoxime as a blocking agent.

6. The method for inkjet textile printing in any one of 1 to 5 abovewherein the aqueous pigment ink is a dispersion liquid containing adispersed pigment having a maximum particle diameter of not more than500 nm.

7. The method for inkjet textile printing in any one of 1 to 6 abovewherein (C) the water-soluble dispersing agent having a crosslinkingproperty results from neutralization, with a basic substance, of anemulsion polymer having a molecular weight of 2,000 to 20,000 obtainedfrom:

-   (1) 20 to 80 parts by weight of a (meth)acrylic acid ester monomer    represented by CH₂═CR⁵—COOR⁶ [wherein R⁵ represents a hydrogen atom    or a methyl group, and R⁶ represents an alkyl group having 2 to 8    carbon atoms.],-   (2) 80 to 20 parts of an aliphatic vinyl monomer having a carboxyl    group, and-   (3) 0 to 20 parts of an aliphatic vinyl monomer having a    crosslinking property.

8. The method for inkjet textile printing in 7 above wherein (2) thealiphatic vinyl monomer having a carboxyl group is at least one selectedfrom the group consisting of acrylic acid, methacrylic acid, itaconicacid, maleic acid, and fumaric acid.

9. The method for inkjet textile printing in 7 or 8 above wherein thebasic substance is a secondary amine or a tertiary amine.

10. The method for inkjet textile printing in any one of 1 to 9 abovewherein the blending ratio of (C) the water-soluble dispersing agenthaving a crosslinking property in the aqueous pigment ink ranges from0.05 to 2.0 parts by weight relative to 1.0 part by weight of thepigment.

11. The method for inkjet textile printing in any one of 1 to 10 abovewherein the aqueous pigment ink contains a polyoxyethylene styrenatedphenyl ether sulfate or a polyoxyethylene alkyl ether sulfate as adispersing aid.

12. The method for inkjet textile printing in any one of 1 to 11 abovewherein (D) the self-emulsifying type urethane resin has been obtainedfrom a composition comprising at least:

-   an isocyanate and-   a polyol having a carboxyl group or a sulfonic acid group.

13. The method for inkjet textile printing in any one of 1 to 12 abovewherein the glass transition point (Tg) of (D) the self-emulsifying typeurethane resin is −60 to 20° C.

14. The method for inkjet textile printing in any one of 1 to 13 abovewherein (E) the block isocyanate compound is a compound resulting fromblocking the isocyanate group in

-   trimethylolpropane adduct form or isocyanurate form of:-   hexamethylene diisocyanate,-   hydrogenated xylylene diisocyanate,-   isophorone diisocyanate, or-   dicyclohexylmethane diisocyanate.

15. The method for inkjet textile printing in 14 above wherein (E) theblock isocyanate compound has been obtained with diethyl malonate,diisopropylamine, 1,2,4-triazole, 3,5-dimethylpyrazole, or2-butanonoxime as a blocking agent.

16. The method for inkjet textile printing in any one of 1 to 15 abovewherein (E) the block isocyanate compound is water-soluble orself-emulsifying, and wherein the aqueous pigment ink is excellentlyredispersible.

17. The method for inkjet textile printing in any one of 1 to 16 abovewherein the viscosity of the aqueous pigment ink is 3 to 30 mPa·s at 20°C.

18. The method for inkjet textile printing in any one of 1 to 17 abovewherein the surface tension of the aqueous pigment ink is 20 to 40 mN/m.

19. The method for inkjet textile printing in any one of 1 to 18 above,having a heat treatment step for heating at least a portion on which anaqueous pigment ink is printed of a textile fiber product on which theaqueous pigment ink is printed by an inkjet process in said printingstep.

20. The method for inkjet textile printing in any one of 1 to 19 abovewherein the pretreatment is performed by applying at least:

-   (A) a cationic surfactant represented by the formula (1) above and-   (B) a block isocyanate compound to the entire textile fiber product    or a required portion thereof by a padding process, coating process,    screen printing process, inkjet process, or spraying process.

21. The method for inkjet textile printing in any one of 1 to 20 above,having a post-treatment step for post-treating at least a portion onwhich an aqueous pigment ink is printed of a textile fiber product onwhich the aqueous pigment ink is printed by an inkjet process in saidprinting step, by a padding process, coating process, screen printingprocess, inkjet process, or spraying process.

22. The method for inkjet textile printing in 21 above wherein thepost-treatment is performed by applying at least one of acrylic resinemulsion, urethane resin emulsion, crosslinking agent, plasticizer,surfactant, and silicone-based softening agent to at least a portion onwhich an aqueous pigment ink is printed of said textile fiber product.

23. A textile fiber product printed by the method for inkjet textileprinting in any one of 1 to 22 above.

[3] The present invention has been developed on the basis of thefindings shown below.

(1) Problems in Inkjet Textile Printing Using a Pigment Ink

Inkjet textile printing using an ink with a pigment as a colorant isexemplified by:

-   a method comprising blending water, a hydrophilic solvent such as a    wetting agent, an emulsion type resin as a binder, and the like with    pigment using a nonionic surfactant or an anionic surfactant as a    pigment-dispersing agent to obtain an ink, and thereafter textile    printing a desired pattern on a textile fiber product with the ink;-   a method comprising printing on a cloth pretreated with a cationic    polymer and an acrylic emulsion resin (adhesive) in advance;-   a method comprising dispersing a pigment using an organic polymer    compound having an anionic group, previously polymerized in a    solvent, then distilling off the solvent, thereafter adding an acid    for acid deposition to cover the pigment surface with the organic    polymer compound, thereafter adding water and a base to obtain a    solubilized microcapsulated pigment, blending a block isocyanate in    this covered pigment to obtain an ink, printing the ink by an inkjet    process, and performing a heat treatment; a method comprising    dispersing a pigment using a water-dispersible resin, adding a block    isocyanate as a crosslinking agent, and performing a heat treatment,    to achieve coloring with excellent fastness;    and the like; however, these methods have the problems shown below.

(1-1) When using a nonionic surfactant or an anionic surfactant as apigment-dispersing agent, a pigment dispersion that possesses excellentlong-term stability and is suitable for inkjet can be obtained becauseof their high dispersion capacity. However, when used to color a textilefiber product, this tends to inhibit pigment binding due to poor fiberaffinity. In addition, the surfactant remaining on the textile fiberproduct has adverse effects on the color fastness to washing and rubbingand the like of the textile fiber product due to the water solubilitythereof.

(1-2) For a microcapsulated pigment prepared by dispersing a pigmentusing an organic polymer compound having an anionic group, subjecting itto acid deposition, and redissolving it using a base, the waterresistance can be improved by covering the pigment surface with theorganic polymer; however, the productivity is poor because extremelycomplex production steps are required. In addition, because aciddeposition and redissolution with a base are required after dispersion,some portion of the pigment flocculates, tending to cause color densityreduction, precipitation and increased viscosity, nozzle clogging, andthe like during long-time storage. In addition, a pigment dispersionprepared using a water-dispersible resin that also serves as a binder isdispersible in water and hence highly oleophilic, resulting in increasedviscosity at the time of pigment dispersion. In addition, when thesolvent water volatilizes, the pigment becomes insoluble in water and islikely to cause clogging at the nozzle tip.

(1-3) In the method wherein a cationic polymer and an acrylic emulsionresin are previously applied to the surface of a textile fiber productto bind a pigment to the textile fiber product, and the surface isinkjet-printed to bind the pigment to the textile fiber product,sufficient fastness cannot be retained because the bound pigment bindsto the surface only ionically. In addition, while the cationic polymeris used in combination with an acrylic resin (adhesive), inkjet printingis performed on a dry resin film, so that the pigment adheres to theresin surface, and the degree of fastness is insufficient. In addition,because a pretreatment agent is applied over the entire textile fiberproduct, the feeling and touch worsen, and the breathability tends to beadversely affected. On the other hand, to bind the pigment to thetextile fiber product surface without pretreatment, it is necessary toblend a large amount of an emulsion resin for binding in the ink.Although the emulsion resin for binding is capable of firmly bonding thepigment to the textile fiber product, it forms a water-insoluble filmupon drying; therefore, large-amount blending thereof can cause inkjetnozzle clogging and hardens the feeling of the colored portion in thetextile fiber product.

(1-4) Although the occurrence of inkjet nozzle clogging due tolarge-amount blending of an emulsion resin in (1-3) above may beprevented by blending a large amount of wetting agent to delay thedrying, blending of a large amount of wetting agent can significantlyreduce the fastness of the colored portion in the textile fiber product,and even when a wetting agent is blended in a large amount, nozzle tipclogging cannot be prevented completely.

(1-5) In the method wherein a block isocyanate and water are added to apigment covered with an organic polymer compound having a carboxylgroup, inkjet printing is performed, and thereafter heating is performedto color a textile fiber product, the pigment can be water-insolubilizedon the textile fiber product surface through the reaction of thecarboxyl group and the isocyanate group; however, as stated above, thecovered pigment in an inkjet ink tends to deteriorate the long-termstorage stability of the inkjet ink due to the complex production steps.In addition, through the reaction of the carboxyl group and theisocyanate group only, it is difficult to obtain sufficient colorfastness (fastness to washing, fastness to rubbing, and the like) at thecolored portion in the textile fiber product.

(2) Solutions to the Problems

(2-1) By applying a particular cationic surfactant to a textile fiberproduct in a pretreatment, an ion complex is formed with an aqueouspigment ink to prevent bleeding and penetration to the maximum possibleextent, thus enabling brilliant printing with high density. Because noresin is used in the pretreatment, the feeling of the textile fiberproduct is not adversely affected.

(2-2) Use of a cationic surfactant in (2-1) above is feared to reducefastness properties such as water resistance; however, by using a blockisocyanate compound in the pretreatment above, and also using awater-soluble dispersing agent having a crosslinking property and aself-emulsifying type urethane resin in the aqueous pigment ink, theblock isocyanate compound in the pretreatment and the water-solubledispersing agent having a crosslinking property and/or the crosslinkingfunctional group in the self-emulsifying type urethane resin in theaqueous pigment ink crosslink with each other, making the pigment, thewater-soluble dispersing agent having a crosslinking property, theself-emulsifying type urethane resin, and the block isocyanate compoundan integral entity, and ensuring sufficient fastness.

(2-3) By blending a pigment dispersion obtained using a water-solubledispersing agent having a crosslinking property, a self-emulsifying typeurethane resin as a binder, and a block isocyanate compound as acrosslinking agent, an aqueous pigment ink for inkjet that is of lowviscosity and high color density and possesses excellent printingworkability and long-term storage stability, is obtained. Furthermore,the block isocyanate compound in the pretreatment and/or the blockisocyanate compound in the aqueous pigment ink and the water-solubledispersing agent having a crosslinking property and/or the crosslinkingfunctional group in the self-emulsifying type urethane resin in theaqueous pigment ink crosslink with each other, whereby they becomewater-insoluble and function as a pigment binder; therefore, a textilefiber product possessing good fastness in the colored portion isobtained while preventing the feeling from being adversely affected.

(3) According to the method for inkjet textile printing of the presentinvention, which is based on the above-described aspects, in addition tothe advantages of conventional inkjet textile printing arising from thepossibility of textile printing without plate making, i.e., small lotsize, multiple varieties, quick delivery, no requirement of plate makingcost, and possibility of extremely efficient textile printing, inkjetprinting of a textile fiber product with an aqueous pigment ink can beperformed brilliantly with high density while preventing bleeding andpenetration to the maximum possible extent by pretreating a textilefiber product with a particular cationic surfactant and block isocyanatecompound, and the block isocyanate compound used in the pretreatmentand/or the block isocyanate compound in the aqueous pigment ink and thewater-soluble dispersing agent having a crosslinking property and/or thecrosslinking functional group in the self-emulsifying type urethaneresin in the aqueous pigment ink crosslink with each other, whereby thewater-soluble dispersing agent, the self-emulsifying type urethaneresin, and the block isocyanate compound become a water-insolubleintegral entity, and, while in a state containing the pigment, bindfirmly to the fiber in the textile fiber product, whereby apigment-colored textile fiber product with soft feeling and excellentfastness is obtained.

In the method for inkjet textile printing of the present invention, anion complex is formed by a particular cationic surfactant and an aqueouspigment ink in a pretreatment, and the block isocyanate compound in thepretreatment and/or the block isocyanate compound in an aqueous pigmentink and the water-soluble dispersing agent having a crosslinkingproperty and/or the crosslinking functional group in theself-emulsifying type urethane resin in the aqueous pigment inkcrosslink with each other, or moreover the block isocyanate compounditself condenses, a desired effect is obtained; if any constituent islacking, the object of the present invention cannot be accomplished.Accordingly, the configuration of the present invention is of particularsignificance.

According to the present invention, by pretreating a textile fiberproduct with a particular cationic surfactant and block isocyanatecompound, inkjet printing of an aqueous pigment ink on the textile fiberproduct can be performed brilliantly with high density while preventingbleeding and penetration to the maximum possible extent, and the blockisocyanate compound used in the pretreatment and/or the block isocyanatecompound in the aqueous pigment ink and the water-soluble dispersingagent having a crosslinking property and/or the crosslinking functionalgroup in the self-emulsifying type urethane resin in the aqueous pigmentink crosslink with each other, whereby the water-soluble dispersingagent, the self-emulsifying type urethane resin, and the blockisocyanate compound become a water-insoluble integral entity, and, whilein a state containing the pigment, bind firmly to the fiber in thetextile fiber product, whereby a pigment-colored textile fiber productwith soft feeling and excellent fastness is obtained.

DETAILED DESCRIPTION OF THE INVENTION

Modes for embodying the present invention are described below.

(1) Textile Fiber Product

Textile fiber products that can serve as the subject for the method forinkjet textile printing of the present invention include fabrics, knits,non-woven fabrics, gigged cloths, and the like configured with variousfibers, whether in the form of material cloths, garments (shirts,sweatshirts, jerseys, pants, one-piece dresses, blouses, hats and caps,socks, and the like), apparel accessories (handkerchiefs, neckties,cloth belts, and the like), or other products (shoes, beddings, bedsheets, curtains, car seats, bags, flags, and the like). Even thosehaving a portion configured with a non-fiber component are, as a rule,not excluded from the scope of the subject.

The fiber that constitutes the textile fiber product, as a rule, is alsosubject to no limitation; for example, the subject may be a textilefiber product configured by any one of various synthetic fibers,semi-synthetic fibers, natural fibers, and inorganic fibers (includingmixed-spun fabrics thereof) such as nylon, polyester, acryl, lactatefiber, acetate, rayon, cotton, silk, wool, hemp, and glass fiber.

Not only for white fiber products, but also for chromatic fiberproducts, a desired pattern and the like including a color image can beformed by, for example, textile printing with a white masking aqueouspigment ink using the method for inkjet textile printing of the presentinvention, and thereafter textile printing with a chromatic aqueouspigment ink using the method for inkjet textile printing of the presentinvention.

(2) Pretreatment

The method for inkjet textile printing of the present inventionencompasses not only methods comprising a pretreatment step for atextile fiber product, but also cases where a pretreatment haspreviously been performed on the textile fiber product.

The pretreatment in the present invention is performed by applying atleast:

-   (A) a quaternary ammonium salt type cationic surfactant represented    by the formula (1) above and-   (B) a block isocyanate compound to the entire textile fiber product    or a required portion thereof.

In this pretreatment, a cationic surfactant of the formula (1) and ablock isocyanate compound may be separately applied to a textile fiberproduct (e.g., impregnated in, or bonded to, the textile fiber product),and a single pretreatment agent containing both may also be applied to atextile fiber product.

(a) Quaternary Ammonium Salt Type Cationic Surfactant Represented byFormula (1)

By applying a quaternary ammonium salt type cationic surfactant of theformula (1) to the entire textile fiber product or a desired portionthereof in the pretreatment, an ion complex is formed with the aqueouspigment ink that is to be subsequently inkjet-printed. For this reason,without causing color fastness reduction, the bleeding and penetrationof aqueous pigment ink is prevented to the maximum possible extent,enabling brilliant inkjet printing with high color density using theaqueous pigment ink.

In the pretreatment, a quaternary ammonium salt type cationic surfactantof the formula (1) can be applied to a textile fiber product in anamount that prevents the bleeding and penetration of the aqueous pigmentink. If the amount applied is large, fastness properties such as waterresistance can decrease, and if the amount applied is small, theprevention of bleeding and penetration can become insufficient.

Any two of R¹ to R⁴ in the formula (1) should be mutually independentlyalkyl groups having 8 to 18 carbon atoms, and the other two should bemutually independently a methyl group or an ethyl group.

When two of the aforementioned four alkyl groups is a methyl group or anethyl group, the quaternary ammonium salt type cationic surfactant ofthe formula (1) becomes water-soluble, and, when constituting apretreatment agent along with a block isocyanate compound, makes thestorage stability of the pretreatment agent good.

If the carbon number of one or both of the other two alkyl groups in theaforementioned four alkyl groups is less than 8, the water resistancedecreases. Meanwhile, if the carbon number of one or both of the twoalkyl groups is more than 18, brilliant inkjet textile printing of anaqueous pigment ink with high color density becomes difficult toperform, and, when the quaternary ammonium salt type cationic surfactantof the formula (1) constitutes a pretreatment agent along with a blockisocyanate compound, the storage stability of the pretreatment agentdecreases due to increased likelihood of phase separation and the like.

The alkyl group having 8 to 18 carbon atoms in the formula (1) may belinear or branched; examples include, but are not limited to, octylgroup, nonyl group, decyl group, dodecyl group, tetradecyl group,octadecyl group, isooctyl group, 2,4-dimethylhexyl group,4-ethyl-2-methylheptyl group, and the like.

For the quaternary ammonium salt type cationic surfactant of the formula(1), when all of the four alkyl groups are methyl groups or ethylgroups, the hydrophilicity increases, but the fastness of the colorsimparted by the aqueous pigment ink decreases. Meanwhile, when all ofthe four alkyl groups have a carbon number of 8 to 18, thehydrophobicity of the surfactant of the formula (1) increases, so thatthe water resistance improves, but water-solubility is not achieved.Furthermore, if only one alkyl group has 8 to 18 carbon atoms, the waterresistance of the surfactant of the formula (1) is insufficient; whentwo alkyl groups have 8 to 18 carbon atoms and the other two alkylgroups are methyl group(s) or ethyl group(s) in a ratio of 1:1 of both,an appropriate balance is obtained between the water solubility and thecolor fastness.

X⁻ in the formula (1) represents an anion. Examples of the anion includehalide ion, inorganic acid ion, organic acid ion, and hydroxide ion.More specific examples of halide ion, inorganic acid ion, and organicacid ion include, but are not limited to, chloride ion, bromide ion,sulfate ion, nitrate ion, phosphate ion, acetate ion, malonate ion, andthe like.

(B) Block Isocyanate Compound

As the block isocyanate compound used in the pretreatment in the presentinvention, one having a group that is reactive with (C) a water-solubledispersing agent having a crosslinking property and (D) a crosslinkingfunctional group in a self-emulsifying type urethane resin upon heating(preferably heating at 100° C. or higher) (e.g., one having 2 or 3 ormore such groups) can be used.

When applying the block isocyanate compound in the present invention toa textile fiber product in pretreatment, the compound crosslinks withthe water-soluble dispersing agent having a crosslinking property andself-emulsifying type urethane resin in the aqueous pigment ink that isto be used for inkjet printing, and they become water-insoluble and bindto the textile fiber product. In addition, the block isocyanate compounditself condenses and binds to the textile fiber product, thus capable ofexhibiting a primer-like function.

In the pretreatment, the block isocyanate compound is preferably appliedto the textile fiber product in an amount at least larger than theamount that just fits the reacting water-soluble dispersing agent havinga crosslinking property and the number of crosslinking functional groupsin the self-emulsifying type urethane resin. If the amount applied istoo large, the feeling of the textile fiber product can harden, and ifthe amount applied is small, the color fastness can decrease.

The block isocyanate compound is preferably a compound resulting fromblocking the isocyanate group in:

-   TMP (trimethylolpropane) adduct form or isocyanurate form of:-   HDI (hexamethylene diisocyanate),-   H6XDI (hydrogenated xylylene diisocyanate),-   IPDI (isophorone diisocyanate), or-   H12MDI (dicyclohexylmethane diisocyanate).    In this case, the blocking agent is preferably DEM (diethyl    malonate), DIPA (diisopropylamine), TRIA (1,2,4-triazole), DMP    (3,5-dimethylpyrazole), or MEKO (2-butanonoxime), which, however,    are not to be construed as limiting.

The block isocyanate compound (B) in the present invention can be usedas an oligomer resulting from reacting some of the isocyanate groupsthereof with polyol, polycarbonate, polyester, or polyether, or thelike.

(3) Pretreatment Agent

The pretreatment agent used to pretreat a textile fiber product in thepresent invention contains at least:

-   (A) a quaternary ammonium salt type cationic surfactant represented    by the formula (1) and-   (B) a block isocyanate compound.

In addition to the above-described components, the pretreatment agentmay be blended as appropriate with water, a water-soluble organicsolvent, an antioxidant, a drying inhibitor, an ultraviolet absorbent, acrosslinking catalyst, a plasticizer, a defoaming agent, and the like.

In the pretreatment agent, the amount blended of the quaternary ammoniumsalt type cationic surfactant represented by the formula (1) can be, forexample, 0.5 to 20% by weight, and the amount blended of the blockisocyanate compound can be, for example, 0.5 to 15% by weight.

The amount blended of the quaternary ammonium salt type cationicsurfactant of the formula (1) in the pretreatment agent need to be anamount that prevents the bleeding and penetration of the aqueous pigmentink, and is preferably not more than 20 parts, more preferably not morethan 10 parts, still more preferably not more than 5 parts, relative to100 parts of the pretreatment agent. If the amount blended is large,color fastness properties such as water resistance decrease, and if theamount blended is small, it is feared that the bleeding and penetrationof the aqueous pigment ink cannot be prevented.

It is desirable that the amount blended of the block isocyanate compoundin the pretreatment agent be an amount larger than the amount that justfits the reacting water-soluble dispersing agent having a crosslinkingproperty and the number of crosslinking functional groups in theself-emulsifying type urethane resin. The amount blended of the blockisocyanate compound relative to 100 parts of the pretreatment agent ispreferably not more than 15 parts, more preferably not more than 10parts, still more preferably not more than 5 parts. If the amountblended is larger than these levels, the feeling of the textile fiberproduct can harden, and if the amount blended is smaller, the colorfastness can decrease.

(4) Method of Pretreatment

The pretreatment in the present invention can be performed by applying acationic surfactant represented by the formula (1) and a blockisocyanate compound (or a pretreatment agent containing at least them)to the entire textile fiber product or a required portion thereof bypadding process, coating process, screen printing process, inkjetprocess, or spraying process.

After thus applying a pretreatment agent and the like to a textile fiberproduct, the textile fiber product can be inkjet-printed with an aqueouspigment ink in a wet state, or after being dried, or after beingsubjected to a heat treatment.

(5) Printing Step

In the method for inkjet textile printing of the present invention, aportion that has been subjected to the aforementioned pretreatment of atextile fiber product is printed with an aqueous pigment ink by aninkjet process.

All of the desired portions in the subject textile fiber product may besubjected to a printing step after completing the pretreatment step forall of the desired portions; in addition, for example, some desiredportions in the subject textile fiber product may be sequentiallysubjected to a pretreatment step, and before completing the pretreatmentstep for all of the desired portions, the portions for which thepretreatment step has been completed may be sequentially subjected to aprinting step.

(6) Aqueous Pigment Ink

In the present invention, the aqueous pigment ink comprises at least apigment, an aqueous liquid as a solvent or dispersion medium, and:

-   (C) a water-soluble dispersing agent having a crosslinking property,-   (D) a self-emulsifying type urethane resin, and-   (E) a block isocyanate compound.

(C) Water-Soluble Dispersing Agent Having a Crosslinking Property

The water-soluble dispersing agent having a crosslinking property in thepresent invention and (D) a self-emulsifying type urethane resincrosslink with (B) the block isocyanate compound in the pretreatmentand/or (E) the block isocyanate compound in the aqueous pigment ink,whereby they become a water-insoluble integral entity, and, while in astate containing the pigment, bind firmly to the fiber in the textilefiber product.

The water-soluble dispersing agent having a crosslinking property in thepresent invention is exemplified by one prepared by neutralizing:

-   (C4) an emulsion polymer consisting of:-   (C1) a (meth)acrylic acid ester monomer,-   (C2) an aliphatic vinyl monomer having a carboxyl group, and-   (C3) an aliphatic vinyl monomer having a crosslinking property with    (C5) a basic substance.

In the present invention, the blending ratio of the water-solubledispersing agent having a crosslinking property in the aqueous pigmentink preferably ranges from 0.05 to 2.0 parts by weight relative to 1.0part by weight of the pigment; if the blending ratio is lower than 0.05,the dispersion viscosity can increase, and if the blending ratio ishigher than 2.0, the time-related viscosity stability can decrease.

(C1) (Meth)Acrylic Acid Ester Monomer

As the (meth)acrylic acid ester monomer, one represented byCH₂═CR⁵—COOR⁶ [wherein R⁵ represents a hydrogen atom or a methyl group,and R⁶ represents an alkyl group having 2 to 8 carbon atoms.] can beused suitably.

When R⁶ is a hydrogen atom or an alkyl group having 1 carbon atom, thecolored portion of the textile fiber product lacks water resistance orbecomes insufficiently resistant to water; when R⁶ is an alkyl grouphaving not less than 9 carbon atoms, the pigment dispersibility worsens;when R⁶ has an aromatic ring, the viscosity of the aqueous pigment inkincreases, and the time-related viscosity stability worsens.

Examples of this (meth)acrylic acid ester monomer include ethyl(meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, pentyl(meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate,2-ethylhexyl (meth)acrylate, and the like. In the present invention,such (meth)acrylic acid ester monomers may be used alone or incombination of two kinds or more.

(C2) Aliphatic Vinyl Monomer Having a Carboxyl Group

Examples of the aliphatic vinyl monomer having a carboxyl group includeacrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaricacid, and the like. In the present invention, such aliphatic vinylmonomers having a carboxyl group may be used alone or in combination oftwo kinds or more.

(C3) Aliphatic Vinyl Monomer Having a Crosslinking Property

As the aliphatic vinyl monomer having a crosslinking property, analiphatic vinyl monomer having a crosslinking functional group otherthan a carboxyl group that is copolymerizable with the aforementioned(meth)acrylic acid ester monomer can be used. Examples include, but arenot limited to, (meth)hydroxy acrylate, (meth)acrylonitrile, acrylamide,vinyl monomers containing a urethane group with a hydroxyl group, epoxygroup-containing vinyl monomers, ester group-containing vinyl monomersformed from a monomer of a higher carboxylic acid and polyalcohol or thelike, silicone group-containing vinyl monomers that form anorganosiloxane and the like, vinylsulfonic acid,2-acrylamide-2-methylpropanesulfonic acid, sulfuric acid esters of2-hydroxyalkyl (meth)acrylate, vinylphosphonic acid, phosphoric acidesters of hydroxyalkyl(meth)acrylate, (meth)acrylate alkylphosphonicacid, vinyl alcohol, N-ethylmethacrylamide, N-isopropylacrylamide,N-vinylpyrrolidone, and the like.

(C4) Emulsion Polymer

The monomer can be polymerized by, for example, vinyl polymerizationusing an ordinary method of emulsification polymerization. For example,a desired emulsion polymer is obtained by carrying out a reaction in thepresence of a polymerization catalyst, (C4-a) an emulsifying dispersingagent, and (C4-b) a chain transfer agent at 50 to 90° C. for about 4 to10 hours.

The ratio of (C1) (meth)acrylic acid ester monomer that is suitable forthe present invention ranges from 20 to 80 parts, more preferably from30 to 70 parts, relative to 100 parts of the total monomer content, andfrom the viewpoint of the fastness of the colored portion, the ratiostill more preferably ranges from 40 to 60 parts. If the ratio is lessthan 20 parts, water resistance is difficult to obtain aftercrosslinking, and if the ratio exceeds 80 parts, the emulsion polymer isunlikely to become water-soluble even when neutralized with a basicsubstance.

From the viewpoint of viscosity reduction at the time of pigmentdispersion and time-related viscosity stability, the ratio of (C2)aliphatic vinyl monomer having a carboxyl group that is suitable for thepresent invention is 80 to 20 parts relative to 100 parts of the totalmonomer content. Preferably, the ratio ranges from 70 to 30 parts, stillmore preferably from 60 to 40 parts. If the ratio exceeds 80 parts,water resistance is difficult to obtain in the colored portion aftercrosslinking, and if the ratio is less than 20 parts, the emulsionpolymer is unlikely to become water-soluble.

The ratio of (C3) aliphatic vinyl monomer having a crosslinking propertythat is suitable for the present invention is 0 to 20 parts, morepreferably 0 to 15 parts, relative to 100 parts of the total monomercontent. If the ratio exceeds 20 parts, the pigment dispersibilitydecreases, and, depending on the kind of monomer, the emulsion polymercannot become water-soluble.

The molecular weight obtained after polymerization may be, for example,2,000 to 20,000, preferably ranges from 3,000 to 10,000. If themolecular weight exceeds 20,000, the dispersion viscosity is likely tobe high, and the pigment dispersibility can decrease. If the molecularweight is less than 2,000, the bindability of the pigment can beinsufficient.

(C4-a) Emulsifying Dispersing Agent

As the emulsifying dispersing agent, a nonionic or anionic surfactant,for example, can be used. In particular, the water resistance of thecolored portion improves when using a reactive surfactant that iscopolymerizable with the monomer at the time of polymerization.

Examples of the reactive surfactant include, but are not limited to,polyoxyethylene alkenyl ether ammonium sulfate, polyoxyethylenenonylpropenylphenyl ether, polyoxyalkylene alkenyl ether ammoniumsulfate, polyoxyalkylene alkenyl ether, and the like. These surfactantsmay be used alone or in combination of two kinds or more.

(C4-b) Chain Transfer Agent

The chain transfer agent is intended to adjust the emulsion polymer to adesired molecular weight of 2,000 to 20,000; examples include mercaptocompounds, carbon tetrachloride, alpha-methylstyrene dimers, and thelike, and use of a mercapto-based chain transfer agent such asn-octylmercaptan, n-dodecylmercaptan, 3-mercapto propionate,3,3′-thiodipropionic acid, or thioglycolic acid is suitable incontrolling the molecular weight.

The amount blended of the chain transfer agent preferably ranges from0.02 to 0.1 (ratio by weight), still more preferably from 0.04 to 0.08,relative to 1.0 of the total monomer content.

(C5) Basic Substance

The basic substance is used as a neutralizing agent for the emulsionpolymer, and may be any basic substance. For example, ammonia, basicmetal salts, primary amine compounds, secondary amine compounds,tertiary amine compounds, and the like can be used. Above all, in viewof increasing the resolubility of the pigment dispersion, it ispreferable that neutralization be performed with a secondary or tertiaryamine compound. The emulsion polymer is neutralized to a pH of 6 to 9with these basic compounds to yield a water-soluble dispersing agenthaving a crosslinking property.

Neutralizing agents include, but are not limited to, isopropylamine,t-butylamine, n-propylamine, N,N-dimethylethanolamine,diethylethanolamine, diethanolamine, triethylamine, triethanolamine, andthe like. These may be used alone or in combination of two kinds ormore.

(D) Self-Emulsifying Type Urethane Resin

The self-emulsifying type urethane resin in the present invention and(C) a water-soluble dispersing agent having a crosslinking propertycrosslink with (B) the block isocyanate compound in the pretreatmentand/or (E) the block isocyanate compound in the aqueous pigment ink,whereby they become a water-insoluble integral entity, and, while in astate containing the pigment, bind firmly to the fiber in the textilefiber product and pigment-color the textile fiber product.

Generally, urethane resins are roughly divided into the water-solubletype, the self-emulsifying type, and the forcibly emulsified type.

A water-soluble type urethane resin has been polymerized using ahydrophilic polyol; because the resin itself is water-soluble, it isdifficult to obtain desired water resistance for the colored portionwhen the resin is blended in the aqueous pigment ink. A forciblyemulsified type urethane resin has been polymerized in the presence of asurfactant; the resin itself is hydrophobic, the particle diameter islarge, film formation is likely to occur when the resin is blended inthe aqueous pigment ink, defective pixels and print irregularity arelikely to occur due to head nozzle tip clogging when continuous printingis performed, and the long-term storage stability of the aqueous pigmentink is low.

Meanwhile, a self-emulsifying type urethane resin has been prepared byconferring a hydrophilic group to one end of urethane resin, andemulsifying the urethane resin in water by the action of the hydrophilicgroup. When blended in an aqueous pigment ink, a self-emulsifying typeurethane resin has a fine particle diameter, is unlikely to form a film,is suitable for continuous printing, and possesses excellent long-termstorage stability. In addition, a self-emulsifying type urethane resinbecomes hydrophobic when crosslinking the terminal hydrophilic groupthereof with a block isocyanate compound, and, along with thecrosslinked form of (C) a water-soluble dispersing agent having acrosslinking property, becomes a pigment binder with excellent fastness.

As the self-emulsifying type urethane resin in the present invention,for example, a self-emulsifying type urethane resin prepared bydispersing in water a urethane prepolymer consisting at least of apolyol, an isocyanate, an anionic group-incorporating polyol whereinsaid anionic group is selected from a carboxyl group and/or a sulfonicacid group using an anionic group-neutralizing agent to elongate thechain can be used.

The aforementioned polyol component is not particularly limited; forexample, polyether polyols, polyester polyols, polyester polycarbonatepolyols, and the like can be used.

More specifically, examples include low-molecular-weight polyols such asethylene glycol, diethylene glycol, 1,2-propylene glycol, 1,3-propyleneglycol, 1,2-butylene glycol, 1,3-butylene glycol, 1,4-butylene glycol,hexamethylene glycol, and ethylene oxide and/or propylene oxide additionproducts of hydrogenated bisphenol A; polyethylene glycol; polypropyleneglycol; polytetramethylene glycol; polyether polyols prepared by addingethylene oxide and/or propylene oxide with such a low-molecular-weightpolyol as an initiator; polyester polyols prepared by an esterificationreaction of such a low-molecular-weight polyol and a polyvalentcarboxylic acid such as oxalic acid, malonic acid, succinic acid, oradipic acid, or an ester, acid anhydride or the like thereof; reactionproducts of a polyester glycol and an alkylene carbonate such aspolycaprolactone polyol; polyester polycarbonate polyols that arereaction products prepared by reacting an organic dicarboxylic acid witha reaction product of ethylene carbonate and a polyhydric alcohol.

The isocyanate is not particularly limited; diisocyanates,polyisocyanates having three or more isocyanate groups in the molecularstructure thereof, and the like can be used.

Examples of diisocyanates include aromatic diisocyanates such astolylene diisocyanate, diphenylmethane-4,4′-diisocyanate, p-phenylenediisocyanate, xylylene diisocyanate, 1,5-naphthylene diisocyanate,3,3′-dimethyldiphenyl-4,4′-diisocyanate, dianisidine diisocyanate, andtetramethylxylylene diisocyanate; alicyclic diisocyanates such asisophorone diisocyanate, dicyclohexylmethane-4,4′-diisocyanate, andnorbornene diisocyanate; aliphatic diisocyanates such as1,6-hexamethylene diisocyanate and lysine diisocyanate; and mixturesthereof.

Examples of polyisocyanates include trifunctional or more highlyfunctional isocyanates such as triphenylmethane triisocyanate,1-methylbenzole-2,4,6-triisocyanate, dimethyltriphenylmethanetetraisocyanate, and mixtures thereof; modification products such ascarbodiimide modification products, isocyanurate modification products,and biuret modification products of these trifunctional or more highlyfunctional isocyanates; block isocyanates resulting from blocking themwith various blocking agents; isocyanurates (trimers) and biuret trimersof the aforementioned diisocyanates, and the like.

As the aforementioned anionic group-incorporating polyol, polyolscontaining a carboxyl group and/or a sulfonic acid group, for example,can be used. Specific examples include, but are not limited to, carboxylgroup-containing polyols such as dimethylol propionic acid, dimethylolbutanoic acid, dimethylol butyric acid, and dimethylol valeric acid; andsulfonic acid group-containing polyols such as 1,4-butanediol-2-sulfonicacid.

Basic compounds can be used as neutralizing agents for anionic groups.Examples include, but are not limited to, ammonia, basic metal salts,primary amine compounds, secondary amine compounds, tertiary aminecompounds, and the like.

Various additives in common use may be added as required to theself-emulsifying type urethane resin of the present invention. Suchadditives include, for example, viscosity regulators, defoaming agents,antioxidants, ultraviolet absorbents, plasticizers, antistatic agents,and the like.

To soften the feeling of the textile fiber product, it is preferablethat the glass transition point (Tg) of the self-emulsifying typeurethane resin of the present invention range from −60 to 20° C. Theglass transition point (Tg) more preferably ranges from −40 to 0° C.,still more preferably from −30 to −10° C.

The self-emulsifying type urethane resin of the present invention isintended to bind a pigment to a textile fiber product, and if the amountblended is large, the fastness improves but the feeling of the coloredportion hardens. Therefore, the amount blended of the self-emulsifyingtype urethane resin relative to 100 parts of the aqueous pigment ink ofthe present invention is preferably not more than 50 parts, morepreferably not more than 30 parts, and still more preferably not morethan 20 parts.

(E) Block Isocyanate Compound

As the block isocyanate compound in the aqueous pigment ink in thepresent invention, one having a group that is reactive with (C) awater-soluble dispersing agent having a crosslinking property and (D) acrosslinking functional group in a self-emulsifying type urethane resinupon heating (e.g., heating at 100° C. or higher) (e.g., one having 2 or3 or more such groups) can be used.

The block isocyanate compound is preferably a compound resulting fromblocking the isocyanate group in

-   TMP (trimethylolpropane) adduct form or isocyanurate form of:-   HDI (hexamethylene diisocyanate),-   H6XDI (hydrogenated xylylene diisocyanate),-   IPDI (isophorone diisocyanate), or-   H12MDI (dicyclohexylmethane diisocyanate).    In this case, the blocking agent is preferably DEM (diethyl    malonate), DIPA (diisopropylamine), TRIA (1,2,4-triazole), DMP    (3,5-dimethylpyrazole), or MEKO (2-butanonoxime), which, however,    are not to be construed as limiting.

The block isocyanate compound (E) in the present invention can be usedas an oligomer resulting from reacting some of the isocyanate groupsthereof with polyol, polycarbonate, polyester, polyether, or the like.

It is preferable that (E) the block isocyanate compound in the presentinvention be blended in an aqueous pigment ink after being renderedwater-soluble or self-emulsifying by providing a hydrophilic group.Thereby the aqueous pigment ink can be made to be of low viscosity andexcellent redispersibility.

It is desirable that the amount blended of the block isocyanate compoundin the aqueous pigment ink be an amount larger than the amount that justfits the reacting water-soluble dispersing agent having a crosslinkingproperty and the number of crosslinking functional groups in theself-emulsifying type urethane resin; the amount blended of the blockisocyanate compound relative to 100 parts of the aqueous pigment ink ispreferably not more than 30 parts, more preferably not more than 20parts, still more preferably not more than 10 parts. If the amountblended is larger, the feeling of the textile fiber product can harden,and if the amount blended is smaller, the color fastness can decrease.

(F) Pigment

As a rule, any pigment can be used for the aqueous pigment ink of thepresent invention, as far as it is a pigment that can be used as acoloring material for fiber products, whether an organic pigment or aninorganic pigment.

For example, black pigments such as carbon black and iron oxide blackpigment; yellow pigments such as azo pigments, imidazolone pigments, andtitanium yellow pigments; red pigments such as azo pigments,quinacridone pigments, chromophtal pigments, diketopyrrolopyrrolepigments, and anthraquinone pigments; blue pigments such asphthalocyanine pigments; white pigments such as titanium oxide, aluminumsilicate, and silicon oxide; orange pigments such as indanthrenepigments; purple pigments such as dioxazine pigments; green pigmentssuch as phthalocyanine pigments; and the like can be used, which,however, are not to be construed as limiting.

(G) Aqueous Liquid

An aqueous liquid is used as a solvent or dispersion medium in theaqueous pigment ink.

As the aqueous liquid, water or a mixture of water and a water-solubleorganic solvent and the like can be used.

Examples of water-soluble organic solvents include, but are not limitedto:

-   glycol and glycerin solvents such as ethylene glycol, diethylene    glycol, triethylene glycol, propylene glycol, butylene glycol,    glycerin, and diglycerin as wetting agents;-   methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol,    t-butanol, 2-pyrrolidone, N-methyl-2-pyrrolidone, propylene glycol    monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol    monomethyl ether, methyl ethyl ketone, ethyl acetate, and ethylene    glycol mono-n-butyl ether as surface tension, solubility, or drying    speed regulators;    and the like. Such water-soluble organic solvents may be used alone    or in combination of two kinds or more.

(7) Preparation of Aqueous Pigment Ink

The aqueous pigment ink in the present invention comprises at least apigment, an aqueous liquid as a solvent or dispersion medium, and:

-   (C) a water-soluble dispersing agent having a crosslinking property,-   (D) a self-emulsifying type urethane resin, and-   (E) a block isocyanate compound.

The aqueous pigment ink in the present invention can be obtained by, forexample, preparing a pigment dispersion from at least:

(F) a pigment, (G) an aqueous liquid as a solvent or dispersion medium,and, (C) a water-soluble dispersing agent having a crosslinkingproperty, and mixing the pigment dispersion and (D) a self-emulsifyingtype urethane resin, (E) a block isocyanate compound, and (G) an aqueousliquid as a solvent or dispersion medium.

This pigment dispersion may have a pigment solid content of, forexample, 5 to 40% by weight, which, however, is not to be construed aslimiting.

The aqueous pigment ink blended with these components can be rendered anink that is suitable for inkjet textile printing by, for example,adjusting the viscosity to a range from 3 to 30 mPa·s at 20° C., oradjusting the surface tension to a range from 20 to 40 mN/m, oradjusting both the viscosity and the surface tension to these ranges,according to the kind and amount of the aqueous liquid as a solvent ordispersion medium, or the kinds and amounts of other components.

Separating coarse pigment particles 500 nm or more in diameter by filterfiltration or centrifugation is preferable for obtaining an ink that issuitable for inkjet printing.

In obtaining the aforementioned pigment dispersion, (I) a dispersing aidmay be used to supplement the dispersing capacity.

In addition, the aqueous pigment ink in the present invention may beblended with, in addition to the above-described components, forexample, a thickener, an ultraviolet absorbent, an antioxidant, alubricant, a wax, a defoaming agent, an antisetting agent, acrosslinking catalyst, a chelating agent, a surfactant, and the like.

(H) Wet Dispersion Using a Milling Machine

The above-described pigment dispersion used to prepare the aqueouspigment ink in the present invention can be obtained by mixing (F) apigment, (G) an aqueous liquid as a solvent or dispersion medium, and(C) a water-soluble dispersing agent having a crosslinking property, aswell as (I) a dispersing aid added as required, and performing wetdispersion using glass beads, zirconia beads, titania beads, or the likein a milling machine (beads mill).

(I) Dispersing Aid

In obtaining a pigment dispersion, a dispersing aid can be used asrequired. By using an anionic surfactant as a dispersing aid tosupplement the dispersing capacity of (C) a water-soluble dispersingagent having a crosslinking property, it is possible to obtain improveddispersion efficiency, pigment particle micronization, and time-relatedstability by suppression of separation, thickening, and the like duringstorage of the aqueous pigment ink.

Examples of anionic surfactants preferred as dispersing aids includepolyoxyethylene styrenated phenyl ether sulfate or polyoxyethylene alkylether sulfate having an HLB of 10 to 16. This is because a pigmentdispersion that has little impact on the color fastness and excellentlong-term storage stability can be obtained. However, the anionicsurfactant that can be used as a dispersing aid in the present inventionis not limited to these examples.

When using a dispersing aid, the blending ratio (weight) is preferablynot more than 0.3 of the dispersing aid relative to 1 of pigment. If theratio of the dispersing aid is more than 0.3, water resistance reductioncan occur.

(8) Inkjet Printing Machine

The choice of inkjet printing machine for printing an aqueous pigmentink by an inkjet process in the printing step is not particularlylimited, but one having a piezo type nozzle head is preferred. In thecase of a thermal type nozzle head, when used for a long time, the blockisocyanate compound in the ink can undergo thermal cleavage,accelerating the crosslinking reaction. The piezo type is free from thisfear; the ink can be stably discharged for a long time.

Examples of such printing machines include, but of course are notlimited to, EPSON PX-V700, EPSON PM-40000PX, Mimaki TX-1600S, FUJIFILMDMP-2831, MASTERMIND MMP8130 (all are trade names), and the like.

(9) Heat Treatment Process

In the method for inkjet textile printing of the present invention, atleast the portion printed with an aqueous pigment ink of a textile fiberproduct whose pretreated portion has been printed with the aqueouspigment ink by an inkjet process in the printing step is subjected to aheat treatment (e.g., at 100° C. or higher).

Thereby the block isocyanate compound used in the pretreatment and/orthe block isocyanate compound in the aqueous pigment ink and thewater-soluble dispersing agent having a crosslinking property and/or thecrosslinking functional group in the self-emulsifying type urethaneresin in the aqueous pigment ink crosslink with each other, whereby theybecome a water-insoluble integral entity, and, while in a statecontaining the pigment, bind firmly to the fiber in the textile fiberproduct and pigment-color the textile fiber product.

Heating temperature and heating time for the heat treatment are chosenin view of the heat resistance of the subject textile fiber product, thecharacteristics of the substances used for textile printing, and thelike. To achieve sufficient crosslinking, the block isocyanate compoundis required to have a temperature of not lower than the dissociationreaction temperature thereof, and the reaction is carried out usually at100 to 220° C. for 1 to 20 minutes, preferably at 100 to 150° C. for 3to 10 minutes, still more preferably at 120 to 150° C. for 3 to 5minutes.

(10) Post-Treatment

By performing a post-treatment via an indispensable heat treatmentprocess for at least the portion printed with an aqueous pigment ink ofa textile fiber product printed with the aqueous pigment ink by aninkjet process in the printing step, additional effects can be obtained,such as improved feeling, improved color fastness, improved slippage,prevention of electrification, and prevention of discoloration.

The post-treatment can be performed by applying one kind or two kinds ormore of acrylic resin emulsions, urethane resin emulsions, crosslinkingagents, plasticizers, surfactants, silicone-based softening agents, andthe like (post-treatment agents) to at least a required portion of thetextile fiber product by padding process, coating process, screenprinting process, inkjet process, spraying process, or the like. Thesepost-treatment agents may be blended with indispensable additives suchas an antistatic agent, ultraviolet absorbent, antioxidant, defoamingagent, and drying inhibitor.

EXAMPLES

The present invention is hereinafter described in further detail withreference to Examples, to which, however, the present invention is notlimited. Note that “parts” as mentioned in Examples and elsewhere mean“parts by weight” unless otherwise stated.

Example 1

<Pretreatment Agent 1>

5 parts of didecyldimethylammonium chloride, 5 parts of Fixer N (tradename for a block isocyanate compound manufactured by Matsui ShikisoChemical Co., Ltd.), and 90 parts of water were mixed with stirring toyield a pretreatment agent 1.

<Method of Pretreatment>

Cotton broadcloth, polyester crepe de chine, and T/C broadcloth wereeach padded with the pretreatment agent 1 at a wringing rate of 60% andthen dried at 60° C. for 10 minutes to yield respective pretreatedcloths 1.

<Water-Soluble Dispersing Agent 1>

One stirrer, one thermometer, and three dropping funnel were set to a1-liter glass flask, 442 parts of water and 15 parts of AQUARON KH-10(trade name for a reactive surfactant manufactured by Dai-ichi KogyoSeiyaku Co., Ltd.) were placed in the flask, the atmosphere was replacedwith nitrogen with stirring, and the flask was heated to 60° C.

Subsequently, various materials were added drop by drop to the flask:

-   a mixture of 100 parts of butyl acrylate, 20 parts of ethyl    acrylate, 30 parts of 2-ethylhexyl acrylate, 150 parts of    methacrylic acid, and 21 parts of THIOKALCOL 20 (trade name for a    chain transfer agent manufactured by Kao Corporation) from the first    dropping funnel,-   an aqueous solution of 3 parts of ammonium persulfate in 108 parts    of distilled water from the second dropping funnel, and-   an aqueous solution of 3 parts of sodium hydrogen sulfite in 108    parts of distilled water from the third dropping funnel.    This dropwise addition was performed concurrently from the three    dropping funnels over 4 hours while keeping the temperature of the    mixture in the flask at 60° C.

After completion of the dropwise addition, a reaction was carried out at60° C. for 1 hour. Subsequently, the reaction product was allowed tocool down to 20° C. and then filtered through a wire net to yield anemulsion polymer having a solid content of 34%. Triethylamine was addedto the emulsion polymer to yield a water-soluble dispersing agent 1having a pH of 8.2 and a molecular weight of 8,000.

<Pigment Dispersion 1>

20 parts of a pigment, 6.5 parts of the water-soluble dispersing agent1, 50 parts of water, 20 parts of diethylene glycol, 3 parts of urea,and 0.5 parts of SN-DEFOAMER 777 (trade name for a defoaming agentmanufactured by San Nopco Limited) were mixed, and this mixture, alongwith zirconia beads 0.3 mm in diameter, was applied to a milling machineand dispersed for 1 hour. Thereafter, the zirconia beads were removed,and the dispersion was filtered through a membrane filter having a porediameter of 0.5 μm to yield a pigment dispersion 1.

Pigment dispersions prepared using as pigments C.I. Pigment yellow 17,C.I. Pigment Red 122, C.I. Pigment Blue 15:3, and carbon black,corresponding to yellow, magenta, cyan, and black, respectively, werenamed pigment dispersion 1-Y, pigment dispersion 1-M, pigment dispersion1-C, and pigment dispersion 1-K, respectively.

<Aqueous Pigment Ink 1>

20 parts of the pigment dispersion 1, 18 parts of glycerin, 20 parts ofSUPERFLEX 460 (trade name for a self-emulsifying type urethane resinmanufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.), 28 parts of water,and 9 parts of Fixer N were mixed with stirring, 5 parts of water orethylene glycol was added to obtain a viscosity of 4 mPa·s at 20° C. anda surface tension of 32 mN/m, whereby an aqueous pigment ink 1 wasobtained.

Aqueous pigment inks 1 prepared using the pigment dispersions 1-Y, 1-M,1-C, and 1-K were named aqueous pigment inks 1-Y, 1-M, 1-C, and 1-K,respectively.

For the aqueous pigment inks with various colors obtained, particle sizewas measured using a particle size analyzer (trade name: MicrotracUPA-EX150; manufactured by Nikkiso Co., Ltd.); no coarse particleshaving a maximum particle diameter of 500 nm or more were detected.

For the various colors of the aqueous pigment inks obtained,time-related stability at 60° C. for 1 week was examined; no remarkablechange was observed in the viscosity or pigment particle diameter.

<Print Evaluation Test>

The aqueous pigment inks of various colors 1-Y, 1-M, 1-C, and 1-K wereeach filled in an inkjet print tester MMP813BT manufactured byMastermind K.K., and inkjet-printed on each pretreated cloth 1;thereafter, the printed cloths were dried at 60° C. for 10 minutes andheated at 150° C. for 3 minutes; colored cloths without bleeding andwith high brilliancy, high color density, and soft feeling wereobtained.

<Print Stability Test>

The aqueous pigment inks of various colors 1-Y, 1-M, 1-C, and 1-K wereeach filled in an inkjet print tester MMP813BT manufactured byMastermind K.K., and continuously printed on each pretreated cloth 1 for10 minutes; good discharge stability and print stability were exhibitedwithout defective pixels, print irregularity, and the like.

Thereafter, the inkjet print tester was stopped, and while in a statefilled in the inkjet print tester, the aqueous pigment inks of variouscolors were allowed to stand at room temperature for 1 week; thereafter,head cleaning was performed, and the inks were continuously printed oneach pretreated cloth 1 for 10 minutes; good discharge stability andprint stability were exhibited without defective pixels, printirregularity, and the like as before the standing.

<Washing Fastness Test>

The colored cloths obtained were subjected to a washing fastness test inaccordance with the JIS L-0217 103 method×5 times (5-grade ratingmethod); good color fastness to washing was exhibited: grade 4 for allof cotton broadcloth, polyester crepe de chine, and T/C broadcloth.

<Test for Color Fastness to Rubbing>

The colored cloths obtained were subjected to a test for color fastnessto rubbing in accordance with the JIS L-0849 test for color fastness torubbing (5-grade rating method); good fastness to rubbing was exhibited:grade 4 for all of cotton broadcloth, polyester crepe de chine, and T/Cbroadcloth in dry rubbing, and grade 3-4 for cotton broadcloth and T/Cbroadcloth and grade 3 for polyester crepe de chine in wet rubbing.

Example 2

<Pretreatment Agent 2>

5 parts of distearyldimethylammonium chloride, 5 parts of Fixer N, and90 parts of water were mixed with stirring to yield a pretreatment agent2.

<Method of Pretreatment>

Cotton broadcloth, polyester crepe de chine, and T/C broadcloth wereeach padded with the pretreatment agent 2 and then dried at 60° C. for10 minutes in the same manner as Example 1 to yield respectivepretreated cloths 2.

<Water-Soluble Dispersing Agent 2>

Starting materials were treated in the same manner as the obtainment ofa water-soluble dispersing agent 1 in Example 1 except that the monomersin the first dropping funnel were replaced with 140 parts of butylacrylate, 20 parts of ethyl acrylate, 30 parts of 2-ethylhexyl acrylate,80 parts of methacrylic acid, 10 parts of acrylic acid, and 20 parts ofhydroxyethyl acrylate, to yield a water-soluble dispersing agent 2having a pH of 8.2 and a molecular weight of 7,000.

<Pigment Dispersion 2>

20 parts of pigment, 28 parts of water-soluble dispersing agent 2, 48.5parts of water, 20 parts of diethylene glycol, 3 parts of urea, and 0.5parts of SN-DEFOAMER 777 were mixed, and this mixture, along withzirconia beads 0.3 mm in diameter, was applied to a milling machine anddispersed for 1 hour. Thereafter, the zirconia beads were removed, andthe dispersion was filtered through a membrane filter with a porediameter of 0.5 μm to yield a pigment dispersion 2.

Pigment dispersions were prepared using the same pigments correspondingto yellow, magenta, cyan, and black as in Example 1, and named pigmentdispersions 2-Y, 2-M, 2-C, and 2-K, respectively.

<Aqueous Pigment Ink 2>

20 parts of the pigment dispersion 2, 18 parts of glycerin, 20 parts ofPERMARIN UA-300 (trade name for a self-emulsifying type urethane resinmanufactured by Sanyo Chemical Industries, Ltd.), 28 parts of water, and9 parts of Fixer N were mixed with stirring, and 5 parts of water orethylene glycol was added to obtain a viscosity of 5 mPa·s at 20° C. anda surface tension of 33 mN/m, whereby an aqueous pigment ink 2 wasobtained.

Aqueous pigment inks 2 prepared using the pigment dispersions 2-Y, 2-M,2-C, and 2-K were named aqueous pigment inks 2-Y, 2-M, 2-C, and 2-K,respectively.

For the aqueous pigment inks with various colors obtained, particle sizewas measured in the same manner as Example 1; no coarse particles havinga maximum particle diameter of 500 nm or more were detected.

For the various colors of the aqueous pigment inks obtained,time-related stability at 60° C. for 1 week was examined; no remarkablechange was observed in the viscosity or pigment particle diameter.

<Print Evaluation Test>

The aqueous pigment inks 2-Y, 2-M, 2-C, and 2-K were subjected to aprint evaluation test on the pretreated cloth 2 in the same manner asExample 1; colored cloths without bleeding and with high brilliancy,high color density, and soft feeling were obtained.

<Print Stability Test>

The aqueous pigment inks 2-Y, 2-M, 2-C, and 2-K were subjected to aprint stability test using the pretreated cloth 2 in the same manner asExample 1; good discharge stability and print stability were exhibitedboth before and after they were allowed to stand.

<Washing Fastness Test>

The colored cloths obtained were subjected to a washing fastness test inthe same manner as Example 1; good color fastness to washing wasexhibited: grade 4 for all of cotton broadcloth, polyester crepe dechine, and T/C broadcloth.

<Test for Color Fastness to Rubbing>

The colored cloths obtained were subjected to a test for color fastnessto rubbing in the same manner as Example 1; good color fastness torubbings was exhibited: grade 4 for all of cotton broadcloth, polyestercrepe de chine, and T/C broadcloth in dry rubbing, and grade 3-4 forcotton broadcloth and T/C broadcloth and grade 3 for polyester crepe dechine in wet rubbing.

Example 3

<Pretreatment Agent 3>

5 parts of didecyldimethylammonium chloride, 5 parts of AQB-102 (tradename for a block isocyanate compound manufactured by Nippon PolyurethaneIndustry Co., Ltd.), and 90 parts of water were mixed with stirring toyield a pretreatment agent 3.

<Method of Pretreatment>

Cotton broadcloth, polyester crepe de chine, and T/C broadcloth wereeach padded with the pretreatment agent 3 and then dried at 60° C. for10 minutes in the same manner as Example 1 to yield respectivepretreated cloths 3.

<Aqueous Pigment Ink 3>

20 parts of the pigment dispersion 1 of Example 1, 18 parts of glycerin,20 parts of PERMARIN UA-300, 28 parts of water, and 9 parts of AQB-102were mixed with stirring, 5 parts of water or ethylene glycol was addedto obtain a viscosity of 5 mPa·s at 20° C. and a surface tension of 32mN/m, whereby an aqueous pigment ink 3 was obtained.

Aqueous pigment inks 3 prepared using the pigment dispersions 1-Y, 1-M,1-C, and 1-K were named aqueous pigment inks 3-Y, 3-M, 3-C, and 3-K,respectively.

For the aqueous pigment inks with various colors obtained, particle sizewas measured in the same manner as Example 1; no coarse particles havinga maximum particle diameter of 500 nm or more were detected.

For the various colors of the aqueous pigment inks obtained,time-related stability at 60° C. for 1 week was examined; no remarkablechange was observed in the viscosity or pigment particle diameter.

<Print Evaluation Test>

The aqueous pigment inks 3-Y, 3-M, 3-C, and 3-K were subjected to aprint evaluation test on the pretreated cloth 3 in the same manner asExample 1; colored cloths without bleeding and with high brilliancy,high color density, and soft feeling were obtained.

<Print Stability Test>

The aqueous pigment inks 3-Y, 3-M, 3-C, and 3-K were subjected to aprint stability test using the pretreated cloth 3 in the same manner asExample 1; good discharge stability and print stability were exhibitedboth before and after the inks were allowed to stand.

<Washing Fastness Test>

The colored cloths obtained were subjected to a washing fastness test inthe same manner as Example 1; good color fastness to washing wasexhibited: grade 4 for all of cotton broadcloth, polyester crepe dechine, and T/C broadcloth.

<Test for Color Fastness to Rubbing>

The colored cloths obtained were subjected to a test for color fastnessto rubbing in the same manner as Example 1; good color fastness torubbings was exhibited: grade 4 for all of cotton broadcloth, polyestercrepe de chine, and T/C broadcloth in dry rubbing, and grade 3-4 forcotton broadcloth and T/C broadcloth and grade 3 for polyester crepe dechine in wet rubbing.

Example 4

<Pigment Dispersion 3>

20 parts of a pigment, 6.5 parts of the water-soluble dispersing agent 2of Example 2, 6 parts of HITENOL NF13 (dispersing aid: trade name for ananionic surfactant manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.), 44parts of water, 20 parts of diethylene glycol, 3 parts of urea, and 0.5parts of SN-DEFOAMER 777 were mixed, and this mixture, along withzirconia beads 0.3 mm in diameter, was applied to a milling machine anddispersed for 1 hour. Thereafter, the zirconia beads were removed, andthe dispersion was filtered through a membrane filter with a porediameter of 0.5 μm to yield a pigment dispersion 3.

Pigment dispersions were prepared using the same pigments correspondingto yellow, magenta, cyan, and black as in Example 1, and named pigmentdispersions 3-Y, 3-M, 3-C, and 3-K, respectively.

<Aqueous Pigment Ink 4>

20 parts of the pigment dispersion 3, 18 parts of glycerin, 20 parts ofSUPERFLEX 460, 28 parts of water, and 9 parts of Fixer N were mixed withstirring, and 5 parts of water or ethylene glycol were added to obtain aviscosity of 5 mPa·s at 20° C. and a surface tension of 31 mN/m, wherebyan aqueous pigment ink 4 was obtained.

Aqueous pigment inks 4 prepared using the pigment dispersions 3-Y, 3-M,3-C, and 3-K were named aqueous pigment inks 4-Y, 4-M, 4-C, and 4-K,respectively.

For the aqueous pigment inks with various colors obtained, particle sizewas measured in the same manner as Example 1; no coarse particles havinga maximum particle diameter of 500 nm or more were detected.

For the various colors of the aqueous pigment inks obtained,time-related stability at 60° C. for 1 week was examined; no remarkablechange was observed in the viscosity or pigment particle diameter.

<Print Evaluation Test>

The aqueous pigment inks 4-Y, 4-M, 4-C, and 4-K were subjected to aprint evaluation test on the pretreated cloth 1 in the same manner asExample 1; colored cloths without bleeding and with high brilliancy,high color density, and soft feeling were obtained.

<Print Stability Test>

The aqueous pigment inks 4-Y, 4-M, 4-C, and 4-K were subjected to aprint stability test using the pretreated cloth 1 in the same manner asExample 1; good discharge stability and print stability were exhibitedboth before and after the inks were allowed to stand.

<Washing Fastness Test>

The colored cloths obtained were subjected to a washing fastness test inthe same manner as Example 1; good color fastness to washing wasexhibited: grade 4 for all of cotton broadcloth, polyester crepe dechine, and T/C broadcloth.

<Test for Color Fastness to Rubbing>

The colored cloths obtained were subjected to a test for color fastnessto rubbing in the same manner as Example 1; good color fastness torubbings was exhibited: grade 4 for all of cotton broadcloth, polyestercrepe de chine, and T/C broadcloth in dry rubbing, and grade 3 forcotton broadcloth and T/C broadcloth and grade 2-3 for polyester crepede chine in wet rubbing.

Example 5

<Method of Pretreatment>

Black cotton broadcloth was padded with the pretreatment agent 1 andthen dried at 60° C. for 10 minutes in the same manner as Example 1 toyield a pretreated cloth 5.

<Pigment Dispersion 5>

Starting materials were treated in the same manner as Example 1 exceptthat titanium oxide was used as a pigment, to yield a pigment dispersion5-W.

<Aqueous Pigment Ink 5>

50 parts of the pigment dispersion 5-W, 18 parts of glycerin, 10 partsof SUPERFLEX 460, 12 parts of water, and 5 parts of Fixer N were mixedwith stirring, and 5 parts of water or ethylene glycol was added toobtain a viscosity of 5 mPa·s at 20° C. and a surface tension of 32mN/m, whereby an aqueous pigment ink 5-W was obtained.

For the aqueous pigment ink 5-W obtained, particle size was measured inthe same manner as Example 1; no coarse particles having a maximumparticle diameter of 500 nm or more were detected.

For the aqueous pigment ink 5-W obtained, time-related stability at 60°C. for 1 week was examined; no remarkable change was observed in theviscosity or pigment particle diameter.

<Print Evaluation Test>

The aqueous pigment ink 5-W was filled in an inkjet print testerMMP813BT, and inkjet-printed on the pretreated cloth 5 to form a whitemasking layer. The aqueous pigment inks 1-Y, 1-M, 1-C, and 1-K wereinkjet-printed on the white masking layer in the same manner as Example1, thereafter, the cloth was dried at 60° C. for 10 minutes and heatedat 150° C. for 3 minutes; colored cloths without bleeding and with highbrilliancy, high color density, and soft feeling were obtained.

<Washing Fastness Test>

The colored cloths obtained were subjected to a washing fastness test inthe same manner as Example 1; good color fastness to washing wasexhibited at grade 4.

<Test for Color Fastness to Rubbing>

The colored cloths obtained were subjected to a test for color fastnessto rubbing in the same manner as Example 1; good color fastness torubbings was exhibited: grade 3-4 in dry rubbing and grade 3 in wetrubbing.

Example 6

<Post-Treatment>

The various colored cloths of Example 1 to 5 were each padded with apost-treatment agent consisting of 5 parts of Fixer N, 3 parts of FasterXA (trade name for an acrylic resin emulsion manufactured by MatsuiShikiso Chemical Co., Ltd.), 5 parts of Abrasion XF (trade name for asilicone-based softening agent manufactured by Matsui Shikiso ChemicalCo., Ltd.), and 87 parts of water at a wringing rate of 65%, and driedat 60° C. for 10 minutes and then heated at 150° C. for 3 minutes.

The post-treated cloths obtained were tested in the same manner as thewashing fastness test and test for color fastness to rubbing performedin the various Examples; various properties of fastness improved byabout 0.5 grades compared with non-post-treated colored cloths, and thefeeling became softer.

Comparative Example 1

The aqueous pigment inks 1-Y, 1-M, 1-C, and 1-K were subjected to aprint evaluation test in the same manner as Example 1 except that nopretreatment was performed; the colored cloths obtained hadunsatisfactory quality with severe bleeding and poor brilliancy.

Comparative Example 2

<Pretreatment Agent NG1>

5 parts of didecyldimethylammonium chloride and 95 parts of water weremixed with stirring to yield a pretreatment agent NG1.

<Method of Pretreatment>

Cotton broadcloth, polyester crepe de chine, and T/C broadcloth wereeach padded with the pretreatment agent NG1 and then dried at 60° C. for10 minutes in the same manner as Example 1 to yield respectivepretreated cloths NG1.

<Print Evaluation Test>

The aqueous pigment inks 1-Y, 1-M, 1-C, and 1-K were subjected to aprint evaluation test on the pretreated cloths NG1 in the same manner asExample 1; colored cloths without bleeding and with high brilliancy,high color density, and soft feeling were obtained.

<Washing Fastness Test>

The colored cloths obtained were subjected to a washing fastness test inthe same manner as Example 1; the washing fastness was worse than inExample 1: grade 3 for all of cotton broadcloth, polyester crepe dechine, and T/C broadcloth.

<Test for Color Fastness to Rubbing>

The colored cloths obtained were subjected to a test for color fastnessto rubbing in the same manner as Example 1; the color fastness torubbing was worse than in Example 1: grade 3 for all of cottonbroadcloth, polyester crepe de chine, and T/C broadcloth in dry rubbing,and grade 2-3 for cotton broadcloth and T/C broadcloth and grade 2 forpolyester crepe de chine in wet rubbing.

Comparative Example 3

<Pretreatment Agent NG2>

5 parts of Fixer N and 95 parts of water were mixed with stirring toyield a pretreatment agent NG2.

<Method of Pretreatment>

Cotton broadcloth, polyester crepe de chine, and T/C broadcloth wereeach padded with the pretreatment agent NG2 and then dried at 60° C. for10 minutes in the same manner as Example 1 to yield respectivepretreated cloths NG2.

<Print Evaluation Test>

The aqueous pigment inks 1-Y, 1-M, 1-C, and 1-K were subjected to aprint evaluation test on the pretreated cloths NG2 in the same manner asExample 1; the colored cloths had unsatisfactory quality with severebleeding and poor brilliancy.

Comparative Example 4

<Pretreatment Agent NG3>

5 parts of lauryltrimethylammonium chloride, 5 parts of Fixer N, and 90parts of water were mixed with stirring to yield a pretreatment agentNG3.

<Method of Pretreatment>

Cotton broadcloth, polyester crepe de chine, and T/C broadcloth wereeach padded with the pretreatment agent NG3 and then dried at 60° C. for10 minutes in the same manner as Example 1 to yield respectivepretreated cloths NG3.

<Print Evaluation Test>

The aqueous pigment inks 1-Y, 1-M, 1-C, and 1-K were subjected to aprint evaluation test on the pretreated cloths NG3 in the same manner asExample 1; colored cloths without bleeding and with high brilliancy,high color density, and soft feeling were obtained.

<Washing Fastness Test>

The colored cloths obtained were subjected to a washing fastness test inthe same manner as Example 1; the washing fastness was worse than inExample 1: grade 3 for all of cotton broadcloth, polyester crepe dechine, and T/C broadcloth.

<Test for Color Fastness to Rubbing>

The colored cloths obtained were subjected to a test for color fastnessto rubbing in the same manner as Example 1; the color fastness torubbing was worse than in Example 1: grade 3-4 for all of cottonbroadcloth, polyester crepe de chine, and T/C broadcloth in dry rubbing,and grade 2-3 for cotton broadcloth and T/C broadcloth and grade 2 forpolyester crepe de chine in wet rubbing.

Comparative Example 5

<Pretreatment Agent NG4>

5 parts of SAFTOMER ST-3300 (trade name for a cationic acrylic resinmanufactured by Mitsubishi Chemical Corporation), 5 parts of Fixer N,and 90 parts of water were mixed with stirring to yield a pretreatmentagent NG4.

<Method of Pretreatment>

Cotton broadcloth, polyester crepe de chine, and T/C broadcloth wereeach padded with the pretreatment agent NG4 and then dried at 60° C. for10 minutes in the same manner as Example 1 to yield respectivepretreated cloths NG4.

<Print Evaluation Test>

The aqueous pigment inks 1-Y, 1-M, 1-C, and 1-K were subjected to aprint evaluation test on the pretreated cloths NG4 in the same manner asExample 1; colored cloths of unsatisfactory quality with slightbleeding, slightly poor brilliancy, low color density, and hard feelingwere obtained.

Comparative Example 6

<Water-Soluble Dispersing Agent NG1>

Starting materials were treated in the same manner as the obtainment ofa water-soluble dispersing agent 1 in Example 1 except that the monomersin the first dropping funnel were replaced with 50 parts of butylacrylate and 250 parts of methacrylic acid, to yield a water-solubledispersing agent NG1 having a pH of 8.1 and a molecular weight of 7,500.

<Pigment Dispersion NG1>

20 parts of a pigment, 6.5 parts of the water-soluble dispersing agentNG1, 50 parts of water, 20 parts of diethylene glycol, 3 parts of urea,and 0.5 parts of SN-DEFOAMER 777 were mixed, and this mixture, alongwith zirconia beads 0.3 mm in diameter, was applied to a milling machineand dispersed for 1 hour; the pigment dispersion obtained was found tobe highly viscous and unusable for obtaining the aqueous pigment ink inthe present invention.

Comparative Example 7

<Pigment Dispersion NG2>

20 parts of a pigment, 7 parts of EMULGEN 108 (trade name for a nonionicsurfactant manufactured by Kao Corporation), 49.5 parts of water, 20parts of diethylene glycol, 3 parts of urea, and 0.5 parts ofSN-DEFOAMER 777 were mixed, and this mixture, along with zirconia beads0.3 mm in diameter, was applied to a milling machine and dispersed for 1hour. Thereafter, the zirconia beads were removed, and the dispersionwas filtered through a membrane filter having pore diameter of 0.5 μm toyield a pigment dispersion NG2.

Pigment dispersions were prepared using the same pigments correspondingto yellow, magenta, cyan, and black as in Example 1, and named pigmentdispersions NG2-Y, NG2-M, NG2-C, and NG2-K, respectively.

<Aqueous Pigment Inks NG1>

Starting materials were treated in the same manner as Example 1 exceptthat the pigment dispersions 1-Y, 1-M, 1-C, and 1-K were replaced withthe pigment dispersions NG2-Y, NG2-M, NG2-C, and NG2-K, to yield aqueouspigment inks NG1-Y, NG1-M, NG1-C, and NG1-K.

The pretreated cloth 1 was inkjet-printed in the same manner as Example1 except that the aqueous pigment inks 1-Y, 1-M, 1-C, and 1-K werereplaced with the aqueous pigment inks NG1-Y, NG1-M, NG1-C, and NG1-K,and the colored cloths obtained were subjected to a washing fastnesstest and test for color fastness to rubbing in the same manner asExample 1; the results were worse than in Example 1: grade 2 of washingfastness for all pretreated cloths 1 and grade 3 of color fastness torubbing for all cloths in dry rubbing and grade 2 for cotton broadclothand T/C broadcloth in wet rubbing.

Comparative Example 8

<Aqueous Pigment Inks NG2>

Starting materials were treated in the same manner as Example 2 exceptthat PERMARIN UA-300 in the aqueous pigment ink 2 was replaced withSUPERFLEX E-4800 (forcibly emulsified urethane resin manufactured byDai-ichi Kogyo Seiyaku Co., Ltd.), to yield aqueous pigment inks NG2-Y,NG2-M, NG2-C, and NG2-K.

For the aqueous pigment inks with various colors obtained, particle sizewas measured in the same manner as Example 1; no coarse particles havinga maximum particle diameter of 500 nm or more were detected.

However, for the various colors of the aqueous pigment inks obtained,time-related stability at 60° C. for 1 week was examined; the viscosityincreased, and coarse particles 500 nm or more in diameter weredetected.

The aqueous pigment inks NG2-Y, NG2-M, NG2-C, and NG2-K were subjectedto a print stability test using the pretreated cloth 2 in the samemanner as Example 1; defective pixels and print irregularity due todrying were seen, and the print stability was poor. Furthermore, theinkjet print tester was stopped, and, while in a state filled in theinkjet print tester, the aqueous pigment inks were allowed to stand atroom temperature for 1 week; thereafter, the inkjet print tester did notrestore the capability of satisfactory inkjet printing, and stabledischarge was not achieved, even after head cleaning was performed.

Comparative Example 9

<Aqueous Pigment Inks NG3>

Starting materials were treated in the same manner as Example 2 exceptthat Fixer N in the aqueous pigment ink 2 was replaced with water, toyield aqueous pigment inks NG3-Y, NG3-M, NG3-C, NG3-K.

The pretreated cloth 1 was inkjet-printed in the same manner as Example1 except that the aqueous pigment inks 1-Y, 1-M, 1-C, and 1-K werereplaced with the aqueous pigment inks NG3-Y, NG3-M, NG3-C, and NG3-K,and the colored cloths obtained were subjected to a washing fastnesstest and a test for color fastness to rubbing in the same manner asExample 1; the results were worse than in Example 1: grade 2-3 ofwashing fastness for all pretreated cloths 1, and grade 3-4 of colorfastness to rubbing for all cloths in dry rubbing and grade 2-3 forcotton broadcloth and T/C broadcloth in wet rubbing.

The above-described results of Examples and Comparative Examplesrevealed that the constituent components of (A) a quaternary ammoniumsalt type cationic surfactant represented by the formula (1), (B) ablock isocyanate compound, (C) a water-soluble dispersing agent having acrosslinking property, (D) a self-emulsifying type urethane resin, and(E) a block isocyanate compound in the present invention are ofparticular significance.

What is claimed is:
 1. A method for inkjet textile printing comprising apretreatment step for performing a pretreatment on a textile fiberproduct and a printing step for printing an aqueous pigment ink on thepretreated portion of the textile fiber product by an inkjet process,wherein said pretreatment is performed by applying at least: (A) aquaternary ammonium salt type cationic surfactant represented by formula(1) below, and (B) a block isocyanate compound to the entire textilefiber product or a required portion thereof, and said aqueous pigmentink comprises at least a pigment, an aqueous liquid as a solvent ordispersion medium, and: (C) a water-soluble dispersing agent having acrosslinking property, (D) a self-emulsifying type urethane resin, whichis not water-soluble, and (E) a block isocyanate compound

in formula (1), two of R¹ to R⁴ mutually independently represent analkyl group having 8 to 18 carbon atoms, the remaining two mutuallyindependently represent a methyl group or an ethyl group, and X⁻represents an anion.
 2. The method for inkjet textile printing accordingto claim 1, wherein (B) the block isocyanate compound is a compoundresulting from blocking of the isocyanate group in trimethylolpropaneadduct form or isocyanurate form of: hexamethylene diisocyanate,hydrogenated xylylene diisocyanate, isophorone diisocyanate, ordicyclohexylmethane diisocyanate.
 3. The method for inkjet textileprinting according to claim 2, wherein (B) the block isocyanate compoundhas been obtained using diethyl malonate, diisopropylamine,1,2,4-triazole, 3,5-dimethylpyrazole, or 2-butanonoxime as a blockingagent.
 4. The method for inkjet textile printing according to claim 1,wherein the aqueous pigment ink is a dispersion liquid containing adispersed pigment having a maximum particle diameter of not more than500 nm.
 5. The method for inkjet textile printing according to claim 1,wherein (C) the water-soluble dispersing agent having a crosslinkingproperty results from neutralization, with a basic substance, of anemulsion polymer having a molecular weight of 2,000 to 20,000 obtainedfrom: (1) 20 to 80 parts by weight of a (meth)acrylic acid ester monomerrepresented by CH₂═CR⁵—COOR⁶, wherein R⁵ represents a hydrogen atom or amethyl group, and R⁶ represents an alkyl group having 2 to 8 carbonatoms, (2) 80 to 20 parts of an aliphatic vinyl monomer having acarboxyl group, and (3) 0 to 20 parts of an aliphatic vinyl monomerhaving a crosslinking property.
 6. The method for inkjet textileprinting according to claim 5, wherein (2) the aliphatic vinyl monomerhaving a carboxyl group is at least one selected from the groupconsisting of acrylic acid, methacrylic acid, itaconic acid, maleicacid, and fumaric acid.
 7. The method for inkjet textile printingaccording to claim 5, wherein the basic substance is a secondary amineor a tertiary amine.
 8. The method for inkjet textile printing accordingto claim 1, wherein the blending ratio of (C) the water-solubledispersing agent having a crosslinking property in the aqueous pigmentink ranges from 0.05 to 2.0 parts by weight relative to 1.0 part byweight of the pigment.
 9. The method for inkjet textile printingaccording to claim 1, wherein the aqueous pigment ink contains apolyoxyethylene styrenated phenyl ether sulfate or a polyoxyethylenealkyl ether sulfate as a dispersing aid.
 10. The method for inkjettextile printing according to claim 1, wherein (D) the self-emulsifyingtype urethane resin has been obtained from a composition comprising atleast: an isocyanate and a polyol having a carboxyl group or a sulfonicacid group.
 11. The method for inkjet textile printing according toclaim 1, wherein the glass transition point (Tg) of (D) theself-emulsifying type urethane resin is −60 to 20° C.
 12. The method forinkjet textile printing according to claim 1, wherein (E) the blockisocyanate compound is a compound resulting from blocking the isocyanategroup in trimethylolpropane adduct form or isocyanurate form of:hexamethylene diisocyanate, hydrogenated xylylene diisocyanate,isophorone diisocyanate, or dicyclohexylmethane diisocyanate.
 13. Themethod for inkjet textile printing according to claim 12, wherein (E)the block isocyanate compound has been obtained with diethyl malonate,diisopropylamine, 1,2,4-triazole, 3,5-dimethylpyrazole, or2-butanonoxime as a blocking agent.
 14. The method for inkjet textileprinting according to claim 1, wherein (E) the block isocyanate compoundis water-soluble or self-emulsifying, and wherein the aqueous pigmentink is redispersible.
 15. The method for inkjet textile printingaccording to claim 1, wherein the viscosity of the aqueous pigment inkis 3 to 30 mPa·s at 20° C.
 16. The method for inkjet textile printingaccording to claim 1, wherein the surface tension of the aqueous pigmentink is 20 to 40 mN/m.
 17. The method for inkjet textile printingaccording to claim 1, having a heat treatment step for heating at leasta portion on which an aqueous pigment ink is printed of a textile fiberproduct on which the aqueous pigment ink is printed by an inkjet processin said printing step.
 18. The method for inkjet textile printingaccording to claim 1, wherein the pretreatment is performed by applyingat least: (A) a cationic surfactant represented by the formula (1) aboveand (B) a block isocyanate compound to the entire textile fiber productor a required portion thereof by a padding process, screen printingprocess, inkjet process, or spraying process.
 19. The method for inkjettextile printing according to claim 1, having a post-treatment step forpost-treating at least a portion on which an aqueous pigment ink isprinted of a textile fiber product on which the aqueous pigment ink isprinted by an inkjet process in said printing step, by a paddingprocess, coating process, screen printing process, inkjet process, orspraying process.
 20. The method for inkjet textile printing accordingto claim 19, wherein the post-treatment is performed by applying atleast one of acrylic resin emulsion, urethane resin emulsion,crosslinking agent, plasticizer, surfactant, and silicone-basedsoftening agent to at least a portion on which an aqueous pigment ink isprinted of said textile fiber product.